diff --git a/winbuild/config.py b/winbuild/config.py
index bd991db16..1b5d5e380 100644
--- a/winbuild/config.py
+++ b/winbuild/config.py
@@ -1,5 +1,6 @@
 import os
 
+SF_MIRROR = 'http://iweb.dl.sourceforge.net'
 PILLOW_DEPENDS_DIR = 'C:\\pillow-depends\\'
 
 pythons = {  # '26': 7,
@@ -18,58 +19,69 @@ libs = {
     #     'version': '2.0'
     # },
     'zlib': {
+        'url': 'http://zlib.net/zlib128.zip',
         'filename': PILLOW_DEPENDS_DIR + 'zlib128.zip',
         'hash': 'md5:126f8676442ffbd97884eb4d6f32afb4',
         'dir': 'zlib-1.2.8',
     },
     'jpeg': {
+        'url': 'http://www.ijg.org/files/jpegsr9b.zip',
         'filename': PILLOW_DEPENDS_DIR + 'jpegsr9b.zip',
         'hash': 'md5:a21b8024d78ba05857a75272b4fa95ec',  # not found - generated by wiredfool
         'dir': 'jpeg-9b',
     },
     'tiff': {
+        'url': 'ftp://ftp.remotesensing.org/pub/libtiff/tiff-4.0.6.zip',
         'filename': PILLOW_DEPENDS_DIR + 'tiff-4.0.6.zip',
         'hash': 'md5:f5b485d750b2001255ed64224b98b857',
         'dir': 'tiff-4.0.6',
     },
     'freetype': {
+        'url': 'http://download.savannah.gnu.org/releases/freetype/freetype-2.6.5.tar.gz',
         'filename': PILLOW_DEPENDS_DIR + 'freetype-2.6.5.tar.gz',
         'hash': 'md5:31b2276515d9ee1c7f37d9c9f4f3145a',
         'dir': 'freetype-2.6.5',
     },
     'lcms': {
+        'url': SF_MIRROR+'/project/lcms/lcms/2.7/lcms2-2.7.zip',
         'filename': PILLOW_DEPENDS_DIR + 'lcms2-2.7.zip',
         'hash': 'sha1:7ff1a5b721ca719760ba6eb4ec6f38d5e65381cf',
         'dir': 'lcms2-2.7',
     },
     'tcl-8.5': {
+        'url': SF_MIRROR+'/project/tcl/Tcl/8.5.19/tcl8519-src.zip',
         'filename': PILLOW_DEPENDS_DIR + 'tcl8519-src.zip',
         'hash': 'sha1:9de57fd34bd688716c16c978db96fa16a5fde924',
         'dir': '',
     },
     'tk-8.5': {
+        'url': SF_MIRROR+'/project/tcl/Tcl/8.5.19/tk8519-src.zip',
         'filename': PILLOW_DEPENDS_DIR + 'tk8519-src.zip',
         'hash': 'sha1:78d0d2c81e024e0b48bfd7b2cc16718f08f46ed9',
         'dir': '',
         'version': '8.5.19',
     },
     'tcl-8.6': {
+        'url': SF_MIRROR+'/project/tcl/Tcl/8.6.5/tcl865-src.zip',
         'filename': PILLOW_DEPENDS_DIR + 'tcl865-src.zip',
         'hash': 'md5:932e360acb40ec760ebeed659bc893de',
         'dir': '',
     },
     'tk-8.6': {
+        'url': SF_MIRROR+'/project/tcl/Tcl/8.6.5/tk865-src.zip',
         'filename': PILLOW_DEPENDS_DIR + 'tk865-src.zip',
         'hash': 'md5:f2f5802a5a3b1f70b906e6930db12089',
         'dir': '',
         'version': '8.6.5',
     },
     'webp': {
+        'url': 'http://downloads.webmproject.org/releases/webp/libwebp-0.5.0.tar.gz',
         'filename': PILLOW_DEPENDS_DIR + 'libwebp-0.5.0.tar.gz',
         'hash': 'sha1:d3de815b272fcf88fc4f2dc1ab65d176bcb8df68',
         'dir': 'libwebp-0.5.0',
     },
     'openjpeg': {
+        'url': SF_MIRROR+'/project/openjpeg/openjpeg/2.1.0/openjpeg-2.1.0.tar.gz',
         'filename': PILLOW_DEPENDS_DIR + 'openjpeg-2.1.0.tar.gz',
         'hash': 'md5:f6419fcc233df84f9a81eb36633c6db6',
         'dir': 'openjpeg-2.1.0',